Improved mode of directing motion



UNITED. STATES PATENT OFFICE..

lANDREV BUCHANAN, OF JERSEY CITY, A SSIGNOR T() HIMSELF AND WILLIAM A. RIGHTER, OF NEWARK, NEW JERSEY.

IMPROVED MODE OF DIRECTING MOTION.

Specification forming part of Letters Patent No. 410,0? 5, dated September 22, 1863.

To all whom it may concern Be it known that I, ANDREW BUCHANAN, of Jersey City, in the county of Hudson and State of New Jersey, have invented a new and Improved Means of Directing Motion in Right Lines; and I do hereby declare that the following is a full, clear, and eXact description of the same, reference being had to the acconpanying drawings, in which- Figure l is a longitudinal vertical section of the valve-chest of a locomotive-engine, illustrating the application of my invention to direct the motion of a slide-valve in such inanner as to prevent unnecessary pressure and friction on the seat, the section being taken in sich plane as to show a side view of my imp lo vement. Fig. 2 is a transverse section corresponding to Fig. l. Fig. 3 exhibits a section of the valve and of my invention parallel with Fig. l. Fig. 4 is a top view of the valvechest with the cap which covers my invention removed.

Similar letters of reference indicate corre sponding parts in the several figures.

There are many instances in machinery in which the direct application of fixed guides to a body which it is desired to move rectilinearly is inapplicable or inconvenient, and to meet such instances what is vtermed a parallel motion 7 has been used, but this does not produce a perfect rectilinear movement.

The object of my invention is to obviate the imperfection of the parallel motion, and to obtain a perfect rectilinear movement of a body Withoutthe application of xed guides directly to it; and to this end it consists in the combination of one or more oscillating and longitudinally-moving arms, by means of an attached slide or roller, with a xed arc or curved surface, whereby a certain point in the said arm or arms is caused in its oscillation to describe a right line and to produce a rectilinear movement of any body that is attached to it at that point.

To enable others skilled in the art to make and use myinvention, I will proceed to describe its application to the slide-valve with reference to the drawings.

A is the valve-chest, of the usual consti uc- Y tion, except that it has in its cover Al a square opening, a a, for the reception of the cast-iron standard B, which is fitted snugly into' recesses cda in the ends of the said opening, and

which is supported by means of set-screws b b, screwing through its anges c cand resting on the top of the cover A. This standard has in its upper part a transverse vertical slot, d, and in its lower part a transverse arcformed slot, e, which may be fitted with steel lining-piecesj'j" at the top and bottom.

C U are two precisely similar arms arranged to oscillate one on each side ofthe standard B, upon a horizontal pin, g, which is inserttd through a slide, h, which is fitted to slide up and down in the vertical slot d, the said pin passing through the upper ends of the 'said rods, and the lower ends of the same being connected rigidly together by means of a cross-piece, D, and connected with the slidevalve E by means of a pin, i, passing through them, through the crosspiece D, and through lugs j j, provided'on the valve. The valve and seat are faced perfectly hat. F is a slide fitted snugly, but to work freely back and fort-h, between the lining-pieces ff ofthe slot ein the standard, and connected with the two oscillating arms() G, by means of apirnlc, passing through it and through the said arms. The said arms passthrough the opening a a in the valve-chest. The arcs of the faces ofthe liningpieces f j" are not arcs of circles, but arcs of varying radius, and their form is obtained by first erecting a perpendicular on a rectilinear base, then taking a line -ot a length equal to the length of the arms between the centers of the holes which receive the pins g and i, and placing the lower end 0f the said line upon the base and the upper end on the perpendicular, and moving the lower point on the base while the upper end is compelled to move on the perpendicular 5 and in this movement two points in the said line, at distances from its ends corresponding with the distance at which the top and bottom of the slide F are desired to be from the centers of the pins g i, will describe the required arcs. The faces having been brought as nearly as possible to this form, the several parts are put in place, and the standard B adjusted by the set-screwsb b to bring` the valve in contact with its seat, and if the valve will not touch every part of its seat, the surfaces of the lining-pieces are nished by scraping in the manner commonly practiced by engineers to obtain a very accurate tit or bearing until the valve touches the seat in every position, which proves that its movement is rectilinear. Vhen the valve will touch equally on every part of the seat, thelsetscrews b b are adjusted to regulate the pressure of the valve on the seat, or set it so that it will just work in contact with the seat without any considerable friction.

The upper lining-piece, f', is represented made adjustable by set-screws to enable it to be accurately adjusted relatively to the lower one, f, and to compensate for wear. The said lining-piecef may be omitted, as the pressure ot' the steam on the back ot' the valve would obviate the necessity of any upper track for the slide F, and keep it always in contact with the face f; but in the application of my invention to most other purposes, the slide will require two guiding-surfaces. like ff. In the operation ofthe valve, or of any other body to which my invention is applied, the rods C C have, besides their 'oscillating movement on the pin g, a longitudinal movement, which is permitted by the slide h and slot d in the standard B.

AThe opening a a and standard B are covered by means ot' a cap, G, which is fitted to the cover A of the valvechest with a steamtightjoint. This cap is made with a broad head,the area of which is nearly equal to that of the valve, and which, though of cast-iron,is

thin enough to have a certain degree of dexibility, and to this head the upper end of the standard B is connected by means of a screwbolt, l, and nut n, in such a manner that a portion of the pressure of the steam on the valve is transferred in a downward direction to the said head. This pressure on the head is counter-acted by the pressure of the steam on the lower side of. the said head, and by screwing down the nut u more or less the upward pressure of the steam on the said head is caused to relieve the valve of a greater or less portion of its pressure, and in this way the pressure and friction ot' the valve on its seat may be regulated.

Instead ofthe slide F, there may be a roller; applied to the pin la, to work between the guides fj", and instead of the two arms C C, a single forked arm may be used. i

What l claim as my invention, and desire to secure by Letters Patent, is

rEhe 'oscillating and longitudinally-moving arms C, slide F` and stationary arc-formed or curved guide ff', the Whole applied in combination with each other and with the body whose motion is to be directed, substantially"l as and for the purpose herein specified.

ANDREW BUCHANAN.

Vitnesses:

M. S. PARTRIDGE, D. L. M. MOORE. 

